• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3714-3732
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• 2019

With the rapid development of network, Intrusion Detection System(IDS) plays a more and more important role in network applications. Many data mining algorithms are used to build IDS. However, due to the advent of big data era, massive data are generated. When dealing with large-scale data sets, most data mining algorithms suffer from a high computational burden which makes IDS much less efficient. To build an efficient IDS over big data, we propose a classification algorithm based on data clustering and data reduction. In the training stage, the training data are divided into clusters with similar size by Mini Batch K-Means algorithm, meanwhile, the center of each cluster is used as its index. Then, we select representative instances for each cluster to perform the task of data reduction and use the clusters that consist of representative instances to build a K-Nearest Neighbor(KNN) detection model. In the detection stage, we sort clusters according to the distances between the test sample and cluster indexes, and obtain k nearest clusters where we find k nearest neighbors. Experimental results show that searching neighbors by cluster indexes reduces the computational complexity significantly, and classification with reduced data of representative instances not only improves the efficiency, but also maintains high accuracy.

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권3호
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• pp.159-165
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• 2019

Background: Dental procedures commonly involve the injection of local anesthetic agents, which causes apprehension in patients. The objective of dental practice is to provide painless treatment to the patient. The purpose of this study was to evaluate the effect of Low Level Laser Therapy (LLLT) in reducing the pain due to local anesthetic injection. Materials and Methods: A prospective, split-mouth study was conducted on 25 patients. In Condition A, LLLT was administered followed by the administration of a standard local anesthetic agent. Patients' perception of pain with use of LLLT was assessed based on a Visual Analogue Scale (VAS). In Condition B, LLLT was directed to the mucosa but not activated, followed by the administration of local anesthesia. VAS was used to assess the pain level without the use of LLLT. Results: Comparison between Condition A and Condition B was done. A P value < 0.001 was considered significant, indicating a definite statistical difference between the two conditions. Conclusion: In our study, we observed that LLLT reduced pain during injection of local anesthesia. Further multi-centric studies with a larger sample size and various modifications in the study design are required.

• 융합경영연구
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• 제11권4호
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• pp.65-76
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• 2023

Purpose: It suggests that in order to compare economic development between large cities, this paper aims to exclude factors such as GDP, trade, manpower, R&D, then present newly an analysis of others (inflation, exports, middle-class, competitiveness, digital). Research design, data, and methodology: In the period of rapid digitalization of the world, we would like to deal with different analysis factors than before. This is because digitalization and prices have the greatest impact on the region in terms of national competitiveness. Random sampling was used as the sample size of this study to generate various values for the annual income of the middle class and the competitiveness index, and the analysis method was used. This is because the income of the middle class can lead the digitalization of the country and accelerate it to standardization. Results: Based on these analysis, it is necessary to reduce the inflation rate of digitalization, it is necessary to lower inflation rates. This can be more fundamental than interest rates. If the demand for digitalization is reduced, national competitiveness, national competitiveness will lower national competitiveness. By building a hub for middle class, you can reduce this inflation rate without China's oversupply. Conclusion: This is because it is difficult to maintain competitiveness through interest rate control, as prices rise, and inflation can become unstable. This study can seek digital acceptance by the middle class as a solution to problems like the regional economic confrontation of new globalization inflation environment.

• 한국항해항만학회지
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• 제48권2호
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• pp.109-115
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• 2024

To develop a shipping company insolvency prediction model, we sampled shipping companies that closed between 2005 and 2023. In addition, a closed company and a normal company with similar asset size were selected as a paired sample. For this study, data of a total of 82 companies, including 42 closed companies and 42 general companies, were obtained. These data were randomly divided into a training set (2/3 of data) and a testing set (1/3 of data). Training data were used to develop the model while test data were used to measure the accuracy of the model. In this study, a prediction model for Korean shipping insolvency was developed using financial ratio variables frequently used in previous studies. First, using the LASSO technique, main variables out of 24 independent variables were reduced to 9. Next, we set insolvent companies to 1 and normal companies to 0 and fitted logistic regression, LDA and QDA model. As a result, the accuracy of the prediction model was 82.14% for the QDA model, 78.57% for the logistic regression model, and 75.00% for the LDA model. In addition, variables 'Current ratio', 'Interest expenses to sales', 'Total assets turnover', and 'Operating income to sales' were analyzed as major variables affecting corporate insolvency.

• 치위생과학회지
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• 제12권2호
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• pp.93-102
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• 2012

보건의료분야의 제반환경의 개선에도 불구하고 국민들의 구강건강상태는 아직도 OECD국가 중에서 매우 열악한 상태이다. 국민들의 구강건강을 효율적으로 증진유지하기 위해서는 중대구강병인 치아우식증을 예방하고 조기에 치료할 수 있는 구강보건진료가 이루어져야 한다. 특히 평생구강건강유지에 중요한 연령층인 초등학교학생들을 대상으로 정기적인 계속구강건강관리제도가 시급히 필요하나 초등학생 대상 계속구강건강관리방식의 치아우식예방관리법의 효과에 관한 사례가 부족한 실정이다. 따라서 광주광역시 소재의 S 치과에 2005년 12월부터 2006년 2월에 내원한 만6세에서 13세 환자 중 환자보호자의 동의를 받은 총 39명을 대상으로 실험군과 대조군으로 분류하여 치아우식활성도와 치아우식경험도를 조사하여 지역사회 치과의원에서 기초자료로 활용할 목적으로 시행한바 다음과 같은 결과를 얻었다. 1. 계속구강건강관리군의 기간별 Alban's test 및 Lactobacillius test 점수는 6개월경과 후 초진시의 1.4배에서 1.5배 감소되었고, 12개월경과 후 초진시의 1.5배에서 1.6배 감소되었다(p<0.001). 2. 계속구강건강관리군의 기간별 간이구강위생지수는 6개월과 12개월경과 후 초진시의 1.6배 감소되었다(p<0.05). 3. 12개월경과 후 우식경험영구치지수는 계속관리군(1.88개)에서 대조군(2.72개)보다 1.4배 감소되었으며, 우식영구치지수는 계속관리군(0.07개)에서 대조군(0.85개)보다 12배 감소되었다(p<0.05). 4. 12개월경과 후 제1대구치건강도는 계속관리군(98.04%)에서 대조군(95.97%)보다 1.02배 높게 나타났다(p<0.05). 이상과 같은 결과에 의하여 지역사회 치과의원에서 지속적인 계속구강건강관리제도를 시행하여 아동의 평생구강건강상태를 유지시켜야 한다고 사료되었다.

• 대한치과교정학회지
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• 제21권1호
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• pp.223-238
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• 1991

This study was carried out in order to findout the amount of tooth movement, the changes arch size and the changes in arch morphology following orthodontic treatment and to provide a guideline for to predict post-treatment arch morphology. The sample group for this study consists of 15 males and 22 females, totalling in 37 persons, who received orthodontic treatment at Orthodontic Department of Dankook Univ. Dental Hospital. They are classified into Extraction Class I treatment group (E I), Non-extraction Class I treatment group (N I), and Non-extraction Class III treatment group (N III), according to their pre-treatment malocclusion state and methods of treatment. Following conclusions and averaged dental arch form for each group were obtained by cephalometric linear measurements and dental arch measurements using pre- and post-treatment lateral cephalograms and plaster study models. 1. Intercanine width were reduced in max. of both EI and NI during the period of treatment, 2. Intermolar width were reduced in max. of EI and increased in max. of NI. Therefore although there was no difference between these two groups before the treatment, intermolar width of the max, of NI was wider than that of E1 after the treatment. 3. PMV-incisor distance and PMV-canine distance were decreased in both max. and mand. of EI and that of NI, during the period of treatment. PMV-molar distance was decreased in both max. and mand. of NI and in mand. of NIII. 4. Items that showed stability during the treatment were: max. & mand. PMV-molar distance, mand. intercanine and intermolar width in EI; mand. intercanine and intermolar width in NI; mand. & max. PMV-incisor distance, PMV-canine distance, max. PMV-molar distance and max. & mand. intercanine and intermolar width in NIII. 5. The differences in averaged canine and molar variances to post-treatment dental arch form were present only in EI and in NI. There was no variance between maxilla and mandible in each group.

• 대한치과교정학회지
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• 제49권3호
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• pp.181-187
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• 2019

Objective: This study investigated the relationship between orthodontic treatment and temporomandibular disorders (TMD) in South Korean population. Methods: This study obtained data from the 2012 Korean National Health and Nutrition Examination Survey. The final sample size was 5,567 participants who were ${\geq}19$ years of age. Logistic regression analysis was performed to evaluate the relationship between orthodontic treatment and TMD. Results: Participants who underwent orthodontic treatment showed higher educational level, lower body mass index, reduced chewing difficulty, and reduced speaking difficulty. The adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for orthodontic treatment and TMD were 1.614 (1.189-2.190), 1.573 (1.162-2.129) and 1.612 (1.182-2.196) after adjusting for age, sex and psychosocial factors. Adjusted ORs and their 95% CIs for orthodontic treatment and clicking were 1.778 (1.289-2.454), 1.742 (1.265-2.400) and 1.770 (1.280-2.449) after adjusting for confounding factors. However, temporomandibular joint pain and functional impairment was not associated with orthodontic treatment. Conclusions: Temporomandibular joint pain and dysfunction was not associated with orthodontic treatment.

• 한국임상약학회지
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• 제33권4호
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• pp.270-277
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• 2023

Background: As per guidelines for treating dyslipidemia, the recommended low-density lipoprotein cholesterol (LDL-C) level in extremely high-risk patients, including those with coronary artery diseases is <55 mg/dL. Although this recommendation has been adopted in the guidelines for dyslipidemia in various countries, there is limited evidence of its efficacy in reducing cardiovascular diseases (CVDs), especially among East Asian patients. This study aimed to investigate whether an LDL-C value below 55 mg/dL is associated with decreased risk of CVDs. Methods: Seven clinical trials including 50,970 patients that compared intensive lipid-lowering therapy with less therapy or placebo in patients who had >6 months of follow-up, those with a sample size of ≥150 were selected as the final literature for analysis. Risk ratios (RR) using random effects were represented with 95% confidence intervals (CI) for the reliability of the results. Results: An LDL-C level of <55 mg/dL was related to significantly reduced events of major CVDs (RR: 0.88; 95% CI: 0.80-0.98) and myocardial infarction (RR: 0.81; 95% CI: 0.73-0.90) and a reduced risk of ischemic stroke (RR 0.79; 95% CI 0.69-0.89, mean follow-up=2 years). However, an LDL-C level below 55 mg/dL did not reduce the incidence of CVD in intensive therapy in East Asian patients. Conclusions: A goal LDL-C value below 55 mg/dL was identified to be related to a decreased risk of developing CVD. However, the relation to LDL-C below 55 mg/dL with a decreased risk of CVD was not observed in East Asian patients.

• 한국재료학회지
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• 제22권11호
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• pp.569-574
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• 2012

Large single grain $Gd_{1.5}Ba_2Cu_3O_{7-y}$ (Gd1.5) bulk superconductors were fabricated by a top-seeded melt growth (TSMG) process using an $NdBa_2Cu_3O_{7-y}$ seed. The seeded Gd1.5 powder compacts with a diameter of 50 mm were subjected to the heating cycles of a TSMG process. After the TSMG process, the diameter of the single grain Gd1.5 compact was reduced to 43 mm owing to the volume contraction during the heat treatment. The superconducting transition temperature ($T_c$) of the top surface of the single grain Gd1.5 sample was as high as 93.5 K. The critical current densities ($J_cs$) at 77 K and 1T and 1.5 T were in ranges of 25,200-43,900 $A/cm^2$ and 10,000-23,000 $A/cm^2$, respectively. The maximum attractive force at 77 K of the sample field-cooled using an Nd-B-Fe permanent magnet (surface magnetic field of 0. 527 T) was 108.3 N; the maximum repulsive force of the zero field-cooled sample was 262 N. The magnetic flux density of the sample field-cooled at 77 K was 0.311T, which is approximately 85% of the applied magnetic field of 0.375 T. Microstructure investigation showed that many $Gd_2BaCuO_5$ (Gd211) particles of a few ${\mu}m$ in size, which are flux pinning sites of Gd123, were trapped within the $GdBa_2Cu_3O_{7-y}$ (Gd123) grain; unreacted $Ba_3Cu_5O_8$ liquid and Gd211 particles were present near the edge regions of the single grain Gd1.5 bulk compact.

• 한국융합학회논문지
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• 제9권1호
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• pp.1-8
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• 2018

본 연구는 기업의 사회적 책임과 감사인 규모가 기업의 신용등급에 어떠한 영향을 미치는지를 실증적으로 분석하였다. 본 연구는 관심변수를 기준으로 2005년부터 2011년까지 경실련 경제정의연구소가 경제정의기업으로 선정한 기업을 대상으로 최종표본 159개 기업/연 자료를 분석하였다. 분석결과는 다음과 같다. 첫째, CSR 항목 중 건전성과 기업의 사회적 책임활동 총점이 높을수록 기업신용등급은 유의하게 높게 나타났다. 이러한 결과는 신용평가기관이 기업의 사회적 책임활동을 긍정적으로 평가하여 신용등급에 반영한다는 것을 의미한다. 그러나 환경보호만족도와 기업신용등급 간에는 반대의 결과가 나타났다. 둘째, CSR 활동 중 공정성과 경제발전기여도가 높고 대형감사인이 감사할수록 기업신용등급은 유의하게 높게 나타났다. 반면, 건전성이 높고 대형감사인이 감사할수록 기업신용등급은 낮게 나타나 신용평가기관이 신용등급을 평가함에 있어 CSR 활동 간에 차별적인 반응이 있는 것으로 파악된다.